February 7, 2009

Weiss from Volunteer Lab Rats posted a cool picture of an old Electric Cannon in the forum. As you know we love coil guns around here! I didn’t realize that this idea had been around for this long though. I would love to see how the coil sequencing circuit was designed back then, I am thinking it would be completely mechanical. It could be as simple as the projectile pressing on some switches as it moves down the barrel to turn off some coils and turn others on.

6 Responses to “Vintage Electric Cannon”

Since this is history and “cool” history I just wanted to add some more cool history her 🙂

A Norwegian physicists, Kristian Olaf Birkeland (http://en.wikipedia.org/wiki/Kristian_Birkeland) was all ready before 1900 experimenting with a electric cannon.
He got a patent for his electric cannon in 1901 and he built a 80 cm long electric cannon that he traveled around in Scandinavia and demonstrated.
He then in 1903 made a 2,5 meters long version of his electric cannon witch he was going to demonstrate to many industry people in hopes of selling his idea and making money of his electric cannon. He did 2 successfully test of the cannon in the morning of Feb.6 1903, but later same day when he demonstrated it for the press and armsindustry, the cannon short circuited and the ball was welded stuck in the barrel. All with a big “BOOM” and “POFF” with flames and lighting arcs coming out of it. Needless to say that the Electric Cannon that Birkeland made did not impress the big chiefs of the armsindustry. The press was horrified of all the BOOM and POFF, and his fiasco make the frontside news next day.

“I would love to see how the coil sequencing circuit was designed back then, I am thinking it would be completely mechanical. It could be as simple as the projectile pressing on some switches as it moves down the barrel to turn off some coils and turn others on.”

If you look carefully at the picture, the sequencer is entirely mechanical.

As the motor turns, the rotary switch rotates. The rotary switch has sequenced contacts,which you can see in black on the image.

That “Dr Kapitza” who shares the credit for this was the real thing – Pyotr Kapitsa who worked at the Cavendish with Ernest Rutherford, went home to Russia and was prevented from leaving by Stalin. Check out his Wikipedia entry – he got a Nobel Prize for the work on low temperature physics and helium II he did in the ’30s.